Automatic slack-adjuster for brakes.



R. F. HAMILTON.

AUTOMATIC SLAGK ADJUSTER FOR BRAKES.

APPLICATION lFILED MAY 9|, 1906.

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AUTOMATIG SLAGK ADJUSTBR FOB BRAKES.

APPLIOATIOH FILE@ HAY 9, 1908.

939,018a Patented Nov.2,19o9.

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l/V V EN TOR )5767/14/70 f.- HAM/L /V UNITED sTATEs PATENT oEEieE.

RICHARD F. HAMILTON, OF NEW YORK, N. Y.

AUTOMATIC SLAGK-ADJUSTER FOR BRAKES.

To all whom it may concern:

Be it known that I, RICHARD F. HAMIL- TON, a. citizen of the UnitedStates, and resident of the borough of Manhattan, city, county, andState of New York, have invented certain new and useful Improvements inAutomatic Slack-Adjusters for Brakes, of which the following is aspecification.

My invention relates to automatic slack adjusters particularly for airbrakes such as are used on railroads and the object of my presentinvention is to provide a simple and strong construction for the aboveindicated purpose, which will take up the entire 'i slack or lost motionupon a single application of the brakes.

Reference is to be had to the accompanying drawings in which- Figure lis a diagrammatic view of the entire mechanism, Fig. 2 is a detail viewof the slack adjuster and its connections, drawn upon an enlarged scale;Fig. 3 illustrates a slightly diliferent form of the mechanism; Fig. 4fillustrates still another form of my invention; Fig. 5 is a perspectiveview of the slide employed in the construction shown in Fig. A; Fig. 6illustrates still a further form of my invention; Fig. T is an enlargeddetail view of the take-up rod shown in Fig. (5 and of the mechanism forholding and releasing it; and Fig. 8 is a tace view ot the retainingmember shown in Figs. G and 7.

In Fig. l, A indicates the brake beams having brake shoes A; these beamsare connected with the dead levers B and live levers C respectively,each live lever being connected with the corresponding dead lever by abottom-rod D; E and F are the cylinder levers connected with the livelevers by the top rods Gr; H is the tie rod connecting the two cylinderlevers, and J is the brake cylinder containing the release spring J(Fig.

and the piston J 2, the rod J 3 of said piston being connected pivotallywith the cylinder lever E by means of the pin N. These parts may beconstructed in substantially the usual way, but I prefer to have thefulcrum B of each dead lever secured to the car bolster or car body andnot to the truck bolster, as it is generally arranged. The t'ulcrum isadjustable in any approved manner, for instance by lia-ving the fulcrumbracket or block provided with a series of openings for the ulcrum pinas shown in Fig. l.

Specification of Letters Patent.

Application filed May 9, 1908.

Patented Nov. 2, 1909.

serial No. 431,766.

piston rod J 3 lis connected positively with an arm so that said armwill move in the same line as the piston rod and to the same extent, orin other words, said arm is rigidly connected with the piston or pistonrod. In

Fig. 9, the arm M is secured to the piston rod J 3 through the medium ofthe same pin N which also connects said piston rod with the cylinderlever E. The arm M is apertured for the passage of a reach rod Oextending therethrough loosely so that the arm may travel along saidreach rod without aifecting its position, except under certaincircumstances presently to be explained.

which the arm M is adapted to travel, is screw-threaded so as to receivenuts O2 forming stops limiting the independent movement of the arm M.These stops may be adjusted to any desired position on the portion O andmay then be locked in position by means of check nuts O3. The reach rodis guided in a suitable stationary member or bracket K which may besecured to the cylinder J. O between said bracket K and the collar O4,rigidly secured to said rod, tends to throw the rod toward the right inFig. 2. The reach rod is further guided in a slide L, guided in abracket R to move in a direction parallel to the movement ot' the pistonJ 2, and preferably in line with said piston. This slide also carries adog l) pivotally supported at P and pressed toward the right by a springP2. These parts are so arranged that the reach rod O may move toward theleft in Fig. l without moving the slide L, but when the reach rod movestoward the right, the dog P will grip the reach rod and will thus causethe slide L to move in unison with the reach rod to the same eX- tent.The slide L is provided with a take-up rod L guided in the support orbracket R and connected with the cylinder lever F pivotally as by meansof a pin Q. A perforated dog S pivotally supported on the bracket R at Sand pressed toward the left in Fig. l by a spring S2 surrounds the rod Lot' the slide L and holds the slide against movement toward the left,but permits it to move toward the right.

The distance between the stops O2 is ad justed until it is equal Vto thenormal travel of l the piston J 2. Thus in the normal operationAccording to my present invention the l of the device the reach rod willremain stathe particular construction illustrated by That portion O ofthe reach rod O, along A spring T coiled on the reach rod tionary. Afterthe brake shoes A have worn a longer travel of the piston will berequired to apply the brakes, and (to the extent that the piston travelexceeds the distance between the stops O2) the reach rod will be carriedto the left with the piston, the dog P allowing such movement to takeplace without affecting the position of the slide L which Vis held bythe dog S against any accidental motion toward the left. lVhen thepiston J 2 returns under the influence of the release spring J the dog Pwill securely grip the right-hand portion or end of the reacli-iod O andthus the slide L carrying said dog will be moved toward the right inunison with the reach rod, thereby shifting the fulcrum of the cylinderlever F toward the right and taking up the slack in the entire levermechanism at both ends of the car. The fulcrum Q will remain in thisiiew position until the brake shoes have worn again, when the adjustingoperation described above will be repeated automatically. lVhenever anyexcess slack exists iii the lever mechanism, it will be taken upentirely at the next release of the brakes. The spring T and collar O*might be omitted in view of the fact that the spring J will return thereach rod toward the right owing to the engagement of the arm M with theright hand stop O2.

The construction shown in Fig. 3 is substantially the same as thatillustrated in Fig. 2, the difference lying exclusively in the retainingdevice connected with the take-up rod L. The bracket It carries theretaining dog S swung from the point S as before described, but inaddition to this I employ a second retaining dog S3 pivoted at S4 on theopposite side of the rod L. A spring S5 is interposed between the tworetaining dogsl or members S, S3 and another spring SG is interposedbetween the bracket R and the retaining dog S3. The operation is thesame as before described, that is, the dogs S, S3 keep the slide L frommoving toward the left but allow it to move toward the right. The twodogs pivoted on opposite sides are somewhat more reliable in operationthan the single dog of Fig. 2.

In the construction illust-rated by Figs. at and 5 the arm m is rigidlysecured to the piston-rod J 3 between the cylinder J and the connectingpin iI. The reach rod 0 is provided with a threaded portion 0', stops02, check-nuts 03 and a collar 0* for the retaining spring Z, in thesame manner as described above. The right hand portion of this reach-rodhas a rack 05, engaged by a pawl or tooth p upon a slide Z. This slideis connected rigidly with the take-up rod Z arranged in line with thepiston rod J 3 and having rack teeth engaged by a pawl s pivoted at s onthe guide r and pressed by a spring s2. The direction of the rack teethof the rods 0 and Z and the position of the pawls 72 and s is such as tosecure the same operation which I have described with reference to Fig.2, that is, when the reach-rod 0 moves toward the left, the pawl 29slips, and the slide Z and take-up rod Z remain stationary, being heldagainst any accidental movement by the pawl s; and when the reach-rod 0moves toward the right it takes the slide Z and take-up rod Z with it,thus adjusting the fulcrum Q, to a new position and taking up the slackas before described.

The construction illustrated by Fig. 6 differs from that of Fig. 2 onlyby the construction of the take-up rod L2 and of the retaining deviceworking in conjunction therewith. This take-up rod is provided with aspiral groove Ls engaged by a nut U. This nut is provided oii one sidewith teeth U engaging corresponding teeth R on the bracket It so thatthe nut can turn in one direct-ion only, as long as it is engaged withsaid teeth. On the other face the nut is preferably provided with a raceto be engaged by balls V interposed between said nut and tlie-adjacentportion of the bracket It. This construction will, like those describedbefore, allow the take-up rod to move toward the right, but not towardthe left. Then it is desired to entirely release the take-up rod so thatthe initial adjustment may be made, the nut U is disengaged from theteeth R by moving it to the right, it being understood that sufficientplay is allowed in the ball race for this purpose and if desired ashifting handle `X pivoted at X and having a roller X2 may be providedfor this purpose.

I claim:

l. In air brake mechanism, the combination with the biake cylinder, itspiston and piston rod, and brake mechanism operated thereby, of atake-up rod connected with the brake mechanism and movable in line withthe piston rod, al reach rod located to one side of the piston rod whichlatter has a limited independent movement after which the piston andreach rod move in unison to the saine extent, retaining means forholdingthe take-rip rod against movement in one direction, and retainingmeans engaging the reach rod adjacent to its axial line and carried bysaid take-up rod to move therewith yet allow the reach rod to moverelatively to said second-named retaining means in the directionopposite to that in which the firstnained retaining means allows thetake-up rod to move.

2. In air brake mechanism, the combination with the brake cylinder, itspiston and piston rod and brake mechanism operated thereby, of a take-updevice connected with the brake mechanism, a retaining means carried bya relatively stationary part of the` structure for holding the take-updevice against movement in one direction, a reach rod relatively towhich the piston has a limn ited independent movement after which thepiston and the reach rod move in unison to the same extent, andretaining means carried by said take-up device to move in unisontherewith in both directions and engaging the reach-rod to allow it tomove relatively to the take-up device only in the direction opposite tothat in which the irst named retaining means allows the take-up deviceto move.

3. In air brake mechanism, the combination with the brake cylinder, itspiston and piston rod, and brake mechanism operated thereby, of an armconnected with the piston rod rigidly, a reach-rod having two stopsadapted to be engaged by said arm, a takeup rod movable parallel withthe pistons path, and connected with the brake mechanism, retainingmeansfor holding the take-up rod against movement in one direction andretaining means for compelling the reach-rod and take-up rod to move inunison in the opposite direction, while leaving the reachrod free tomove independently in the same direction in which the take-up rod isprevented from moving.

4. In air brake mechanism, the combination with the brake cylinder, itspiston and piston rod, and brake mechanism operated thereby, of atake-up device connected with the brake mechanism and movable in linewith the piston rod, an arm rigidly secured to the piston rod andprojected therefrom laterally, a reach-rod arrange-d laterally of thepiston rod and relatively to which the said arm has a limited movementafter which the arm and reachnrod move in unison to the same extent,retaining means for holding the take-up device against movement in onedirection, and' retaining means for holding the reach-rod againstmovement relatively to the take-up device in the opposite direction.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses this tenth day of April, 1908.

RICHARD F. HAMILTON.

lVitnesses JOHN Lorna, JOHN A. KEH'IJENBECK.

